• Journal of Korean Society of Steel Construction
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• v.29 no.3
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• pp.193-204
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• 2017

Fatigue strength of temporary steels and painted structural steels corroded under outdoor atmospheric environments is not clear. In this study, fatigue tests were carried out on steel plates which were cut off from 7-year-old temporary structural member under subway construction environment and from 75-year-old Yeongdo bridge member under marine atmospheric environment. After removing corrosion production on the steel surface, 3-dimensional surface geometry of the corroded steel was measured at intervals of $1.0{\times}1.0mm$, and corrosion characteristics such as minimum, maximum and mean values of residual thicknesses were calculated. From the fatigue test and FEM analysis results, the relationship between corrosion characteristics and fatigue behavior was presented, and change in fatigue strength of the unpainted and painted steels corroded in outdoor environments was also presented.

• Journal of the Korean Wood Science and Technology
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• v.18 no.3
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• pp.53-68
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• 1990

This research has been executed for maximization of lumber yield and more efficient use of small diameter logs. Sample logs from thinnings carne from densed artificial stands at the Kwangnung Experimental Forests situated in the central region of Korean peninsula. Species of sample logs were obtained to execute sawing and strength test for larch, and lumber strength test in full size for pitch pine and Korean pine. A survey on sawmills consuming domestic logs was carried out to know sawmill production, costs and utilization structure of lumber as a guide to business analysis. Results showed that sawing pattern from small logs less than 15cm in diameter was necessary to cut 9cm by 9cm square per one log in order to obtain high lumber recovery and provide for wide market needs. The total lumber yield of squares plus side boards was 56 percent to 58 percent from small logs and the yield for log sweep in 30 percent decreased by 24.5 percent in sawing production, compared to yield for straight logs. In sawing efficiency, production of lumber by twin band saw could be improved 238 percent higher than lumber of the same species produced by conventional sawmilling methods, and sawing accuracy with twin band saw was much higher at the lumber production than band saw. Lumber from the small larch logs has shown 70 knots per $m^2$ on its faces and also lumber showed lots of face checkings by air drying on the yard, compared to other species. MOR in bending of lumber in full size from small logs of larch was found ranging from 380kg/$cm^2$ to 460kg/$cm^2$, resulting in 40 percent less than the strength from clear small specimens. In lumber containing knots, cross grain, etc, longitudinal stress wave speed was delayed about 48 percent by defects in lumber from both larch and pitch pine logs. The surveyed sample sawmills consumed the domestic logs at the rate of 54 percent to 84 percent in the total timber consumption, showing high consumption at mills located in the mountains.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.9-14
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• 1986

The rootability of hardwood cutting of mulberry (Morus alba L.) depending upon the kinds of cutting beds, soil of cutting beds, effect of growth regulator (Rootone-F), pretreatments of cutting scion, parts of branches were investigated, The results were as follows ; 1. Rootability was the highest in cutting after callus formed on sand bed, whereas null in the treatment of rice seedling hot bed. 2. Optimum cutting season was around March 26, showed 100% rootability in all treatments except wooden box filled with sand. 3. The order of rootability related with cutting part of branch was upper$^{\circ}C$), and cutting after formation of callus increased rootability, whereas cuttings left in open air for 5 days showed null rootability.

• Fashion & Textile Research Journal
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• v.8 no.4
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• pp.413-419
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• 2006

This study was performed to analyze the wearing practice and the purchasing characteristics of jeans in order to offer basic data to produce superior jeans made of denim with small flexibility and to improve the wearing comfort. The questionnaire were 236 Korean women from the age of 10th to 50th. For data analysis, descriptive analysis and crosstabs were used. The results were as follows, in the purchasing characteristics, when the women of 10th to 30th decided to purchase jeans they considered fashion, design and price rather than wearing comfort. But the women of 40th to 50th considered that wearing comfort is the most important factor. The 10th is found the best preferred jean is wide straight style, the 20th is straight style, the 30th is boots cut style and the 40th to 50th is straight style. In wearing practice, there was a difference among age groups on the region that felt uncomfortable when wearing jeans. As the age increases, the abdomen size also increases. Most people answered that they mend jeans after purchase for length, without any relation with age. The reason why consumers prefer jeans with middle length between the crotch and waist and also purchase jeans with a short length is because they look refined and neat. This informs us that the short length between the crotch and waist does not match with ease and comfort, which are the images of jeans in the past. Recently premium jean brands are competing to show Low Rise Jeans, which seems like a Premium Jean=Low Rise Jean formula is created. Some manufacture companies are recklessly copying foreign designs that does not fit Korean's body shape. However, as mentioned in this study results, there is a clear difference between designs that they think consider as aesthetic and functional. Therefore, it is considered necessary for developing designs for jeans that can satisfy both aesthetic appreciation and functions for Korean consumer's body shape and each age group.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.632-632
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• 2009

The purpose of this study is to present the range of defects mentioned in the Product Liability (PL) and to establish an objective basis and grounds for the analysis of accidents expected to happen by analyzing and presenting the external flame pattern and electrical characteristics of an LED streetlight lamp, a new lighting lamp. From the analysis of the cross-section of a cable carbonized by an external flame, it was observed that the wire's strand and insulation material had solidly adhered, and that greater voids were formed at the surface than at the center. Irregular carbide lumps were formed in the globe directly exposed to the flame, and the globe carbonized by the indirect flame showed characteristics that they had melted and flowed downward. It was found that the forward and backward resistances of the normal LED were approximately 1.74 [$M{\Omega}$] and 140 [$M{\Omega}$], respectively. The lamp burnt by the strong flame exhibited infinite forward and backward resistances and the LED did not emit light. The carbonized LED lamp was gray and exhibited fine delaminations. According to the Product Liability, a product defect signifies a simple product defect. Most of the defects were caused by the lack of stability, and the defect of the product itself occurred during the design and manufacture. The defects in warnings and markings include an insufficiency of handling manuals and warnings, expressive warranty violations, defective markings, etc. In order to prevent an accident resulting from a product, it is necessary to prepare safety warnings and documentation, establish clear-cut lines of liabilities, and subscribe insurances. However, it could be seen that important factors against the Product Liability were product improvement, response to compensation requests and law suits, credit restoration, etc.

• Journal of the Korean Society for information Management
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• v.25 no.2
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• pp.49-68
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• 2008

In many information retrieval experiments, the data fusion techniques have been used to achieve higher effectiveness in comparison to the single evidence-based retrieval. However, there had not been many image retrieval studies using the data fusion techniques especially in combining retrieval results based on multiple retrieval methods. In this paper, we describe how the image retrieval effectiveness can be improved by combining two sets of the retrieval results using the Sobel operator-based edge detection and the Self Organizing Map(SOM) algorithms. We used the clip art images from a commercial collection to develop a test data set. The main advantage of using this type of the data set was the clear cut relevance judgment, which did not require any human intervention.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.79-91
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• 2009

The government separated and established the industrial safety and health law from the Labor Standard law since 1981 to promote the labor's working environment and to improve the conditions of laborers. The government made a lot of effort to discharge the industrial safety and health law by continuous revision of the law thereafter. it is, however, difficult to establish clear-cut lines of authority and responsibility due to the fact that the substantial application of the industrial safety and health law is adapted by enterprise's autonomous management. There are frequent industrial disasters on the small and medium enterprises which have financial difficulty and it means this causes much more social cost. Finally, for the improvement of laborer's safety, health and working environment in the small and medium enterprises we need to raise the effectiveness of the industrial safety and health law through enhancing a government-office's administration and surveillance with the changing mind of a business proprietor. On this paper, we research on the actual condition of the administration, inspection and regulation of safety and health by means of the industrial safety and health law. Thereafter we analyze how much the Korea Occupational Safety & Health Agency and vicarious businesses of safety & health management help. we used the survey method to gather data from 380 laborers directly and analysed the data by SPSS v17.0.

• Journal of Ecology and Environment
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• v.35 no.3
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• pp.177-188
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• 2012

We analyzed crown development in Aucuba japonica Thunb. var. japonica resulting from the responses of phytoelements to habitat light conditions over a long period of time. Over the years, the degree of extension unit (EU) dimorphism and the degree of anisophylly were higher under shaded conditions than in brighter conditions. An overall temporally increasing pattern in the degree of EU dimorphism was found while no clear-cut trend was found in the case of anisophylly. EU length and number of leaves per EU co-varied in a spatio-temporal context. The number of terminal buds and their sizes acted as the key initiators of morphological differences of phytoelements which were further amplified following bud break. Leaf area density was displayed mostly in the apex peripheral layer of the crown and the apex layer received most of the incident light. There was a tradeoff between annual leaf production and mean leaf size. Depending on the heterogeneity of irradiance level within a crown, correlative growth inhibition caused higher EU mortality at brighter sites. Due to high mortality, shorter EUs had a mere role in the construction of structural framework of the crown except for the formation of some gaps. There was a strong convergence of EU dimorphism, anisophylly, EU extension growth and variations in leaf size towards formation of functional crown to reduce potential self-shading. Depending on the irradiance level, Aucuba japonica Thunb. var. japonica showed two different modes of crown expansion. At the brighter sites, individual crown expansion was progressive while at the darker sites, individual crown expanded in a diminishing manner and maintained a stable size. A plant's "growth diminishing phase" appeared earlier at shaded sites than brighter sites.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.34-42
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• 2011

In an effort to the practical realization of phonetic typewriter, we concentrate on the classification of consonants in this paper. Since many of consonants do not show periodic behavior in time domain and thus the validity for Fourier analysis of them are not convincing, vector quantization (VQ) via LBG clustering is first performed to check if the feature vectors of MFCC and LPCC are ever meaningful for consonants. Experimental results of VQ showed that it's not easy to draw a clear-cut conclusion as to the validity of Fourier analysis for consonants. For classification purpose, two kinds of neural networks are employed in our study: self organizing map (SOM) and learning vector quantization (LVQ). Results from SOM revealed that some pairs of phonemes are not resolved. Though LVQ is free from this difficulty inherently, the classification accuracy was found to be low. This suggests that, as long as consonant classification by LVQ is concerned, other types of feature vectors than MFCC should be deployed in parallel. However, the combination of MFCC/LVQ was not found to be inferior to the classification of phonemes by language-moded based approach. In all of our work, LPCC worked worse than MFCC.

• Progress in Medical Physics
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• v.27 no.2
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• pp.55-63
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• 2016

We studied the method to gain a clear LSF using a thick aluminum sheet and to acquire the spatial resolution value with a high accuracy for a low spatial resolution imaging modality. In this study, aluminum sheets with thicknesses varying from 0.3 mm to 1.2 mm were tested to derive a modulation transfer function (MTF) for the oversampling and non-oversampling methods. The results were evaluated to verify the feasibility of the use of thick sheets for periodic quality assurance. Oversampling was more accurate than non-oversampling, and an aluminum sheet with a correction factor less than 2 at the cut-off frequency, which was less than 0.8 mm in this case, was confirmed to be suitable for MTF measurements. Therefore, MTF derivation from a thick aluminum sheet with thickness correction is plausible for a medical imaging modality.